file.c

第二层隧道模块l2tp源码,开发环境为linux

/*
 * Layer Two Tunnelling Protocol Daemon
 * Copyright (C) 1998 Adtran, Inc.
 * Copyright (C) 2002 Jeff McAdams
 *
 * Mark Spencer
 *
 * This software is distributed under the terms
 * of the GPL, which you should have received
 * along with this source.
 *
 * File format handling
 *
 */

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <netdb.h>
#include <netinet/in.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>

#include "l2tp.h"

struct lns *lnslist;
struct lac *laclist;
struct lns *deflns;
struct lac *deflac;
struct global gconfig;
char filerr[STRLEN];

int parse_config (FILE *);
struct keyword words[];

int init_config ()
{
    FILE *f;
    int returnedValue;

    gconfig.port = UDP_LISTEN_PORT;
    lnslist = NULL;
    laclist = NULL;
    deflac = (struct lac *) malloc (sizeof (struct lac));

    f = fopen (gconfig.configfile, "r");
    if (!f) 
    {
        f = fopen (gconfig.altconfigfile, "r");
        if (f)
        {
            strncpy (gconfig.authfile, gconfig.altauthfile, 
            	sizeof (gconfig.authfile));
        }
        else
        {
            log (LOG_CRIT, "%s: Unable to open config file %s or %s\n",
                 __FUNCTION__, gconfig.configfile, gconfig.altconfigfile);
            return -1;
        }

    }
    returnedValue = parse_config (f);
    fclose (f);
    return (returnedValue);
    filerr[0] = 0;
}

struct lns *new_lns ()
{
    struct lns *tmp;
    tmp = (struct lns *) malloc (sizeof (struct lns));
    if (!tmp)
    {
        log (LOG_CRIT, "%s: Unable to allocate memory for new LNS\n",
             __FUNCTION__);
        return NULL;
    }
    tmp->next = NULL;
    tmp->exclusive = 0;
    tmp->localaddr = 0;
    tmp->tun_rws = DEFAULT_RWS_SIZE;
    tmp->call_rws = DEFAULT_RWS_SIZE;
    tmp->hbit = 0;
    tmp->lbit = 0;
    tmp->authpeer = 0;
    tmp->authself = -1;
    tmp->authname[0] = 0;
    tmp->peername[0] = 0;
    tmp->hostname[0] = 0;
    tmp->entname[0] = 0;
    tmp->range = NULL;
    tmp->lacs = NULL;
    tmp->passwdauth = 0;
    tmp->pap_require = 0;
    tmp->pap_refuse = 0;
    tmp->chap_require = 0;
    tmp->chap_refuse = 0;
    tmp->idle = 0;
    tmp->pridns = 0;
    tmp->secdns = 0;
    tmp->priwins = 0;
    tmp->secwins = 0;
    tmp->proxyarp = 0;
    tmp->proxyauth = 0;
    tmp->challenge = 0;
    tmp->debug = 0;
    tmp->pppoptfile[0] = 0;
    tmp->t = NULL;
    return tmp;
}

struct lac *new_lac ()
{
    struct lac *tmp;
    tmp = (struct lac *) malloc (sizeof (struct lac));
    if (!tmp)
    {
        log (LOG_CRIT, "%s: Unable to allocate memory for lac entry!\n",
             __FUNCTION__);
        return NULL;
    }
    tmp->next = NULL;
    tmp->rsched = NULL;
    tmp->localaddr = 0;
    tmp->remoteaddr = 0;
    tmp->lns = 0;
    tmp->tun_rws = DEFAULT_RWS_SIZE;
    tmp->call_rws = DEFAULT_RWS_SIZE;
    tmp->hbit = 0;
    tmp->lbit = 0;
    tmp->authpeer = 0;
    tmp->authself = -1;
    tmp->authname[0] = 0;
    tmp->peername[0] = 0;
    tmp->hostname[0] = 0;
    tmp->entname[0] = 0;
    tmp->pap_require = 0;
    tmp->pap_refuse = 0;
    tmp->chap_require = 0;
    tmp->chap_refuse = 0;
    tmp->t = NULL;
    tmp->redial = 0;
    tmp->rtries = 0;
    tmp->rmax = 0;
    tmp->challenge = 0;
    tmp->autodial = 0;
    tmp->rtimeout = 30;
    tmp->active = 0;
    tmp->debug = 0;
    tmp->pppoptfile[0] = 0;
    tmp->defaultroute = 0;
    return tmp;
}

int yesno (char *value)
{
    if (!strcasecmp (value, "yes") || !strcasecmp (value, "y") ||
        !strcasecmp (value, "true"))
        return 1;
    else if (!strcasecmp (value, "no") || !strcasecmp (value, "n") ||
             !strcasecmp (value, "false"))
        return 0;
    else
        return -1;
}

int set_boolean (char *word, char *value, int *ptr)
{
    int val;
#ifdef DEBUG_FILE
    log (LOG_DEBUG, "set_%s: %s  flag to '%s'\n", word, word, value);
#endif /* ; */
    if ((val = yesno (value)) < 0)
    {
        snprintf (filerr, sizeof (filerr), "%s must be 'yes' or 'no'\n",
                  word);
        return -1;
    }
    *ptr = val;
    return 0;
}

int set_int (char *word, char *value, int *ptr)
{
    int val;
#ifdef DEBUG_FILE
    log (LOG_DEBUG, "set_%s: %s  flag to '%s'\n", word, word, value);
#endif /* ; */
    if ((val = atoi (value)) < 0)
    {
        snprintf (filerr, sizeof (filerr), "%s must be a number\n", word);
        return -1;
    }
    *ptr = val;
    return 0;
}

int set_string (char *word, char *value, char *ptr, int len)
{
#ifdef DEBUG_FILE
    log (LOG_DEBUG, "set_%s: %s  flag to '%s'\n", word, word, value);
#endif /* ; */
    strncpy (ptr, value, len);
    return 0;
}

int set_port (char *word, char *value, int context, void *item)
{
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_GLOBAL:
#ifdef DEBUG_FILE
        log (LOG_DEBUG, "set_port: Setting global port number to %s\n",
             value);
#endif
        set_int (word, value, &(((struct global *) item)->port));
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);
        return -1;
    }
    return 0;
}

int set_rtimeout (char *word, char *value, int context, void *item)
{
    if (atoi (value) < 1)
    {
        snprintf (filerr, sizeof (filerr),
                  "rtimeout value must be at least 1\n");
        return -1;
    }
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_LAC:
#ifdef DEBUG_FILE
        log (LOG_DEBUG, "set_rtimeout: Setting redial timeout to %s\n",
             value);
#endif
        set_int (word, value, &(((struct lac *) item)->rtimeout));
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);
        return -1;
    }
    return 0;
}

int set_rws (char *word, char *value, int context, void *item)
{
    if (atoi (value) < -1)
    {
        snprintf (filerr, sizeof (filerr),
                  "receive window size must be at least -1\n");
        return -1;
    }
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_LAC:
        if (word[0] == 'c')
            set_int (word, value, &(((struct lac *) item)->call_rws));
        if (word[0] == 't')
        {
            set_int (word, value, &(((struct lac *) item)->tun_rws));
            if (((struct lac *) item)->tun_rws < 1)
            {
                snprintf (filerr, sizeof (filerr),
                          "receive window size for tunnels must be at least 1\n");
                return -1;
            }
        }
        break;
    case CONTEXT_LNS:
        if (word[0] == 'c')
            set_int (word, value, &(((struct lns *) item)->call_rws));
        if (word[0] == 't')
        {
            set_int (word, value, &(((struct lns *) item)->tun_rws));
            if (((struct lns *) item)->tun_rws < 1)
            {
                snprintf (filerr, sizeof (filerr),
                          "receive window size for tunnels must be at least 1\n");
                return -1;
            }
        }
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);
        return -1;
    }
    return 0;
}

int set_rmax (char *word, char *value, int context, void *item)
{
    if (atoi (value) < 1)
    {
        snprintf (filerr, sizeof (filerr), "rmax value must be at least 1\n");
        return -1;
    }
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_LAC:
#ifdef DEBUG_FILE
        log (LOG_DEBUG, "set_rmax: Setting max redials to %s\n", value);
#endif
        set_int (word, value, &(((struct lac *) item)->rmax));
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);
        return -1;
    }
    return 0;
}

int set_authfile (char *word, char *value, int context, void *item)
{
    if (!strlen (value))
    {
        snprintf (filerr, sizeof (filerr),
                  "no filename specified for authentication\n");
        return -1;
    }
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_GLOBAL:
#ifdef DEBUG_FILE
        log (LOG_DEBUG, "set_authfile: Setting global auth file to '%s'\n",
             value);
#endif /* ; */
        strncpy (((struct global *) item)->authfile, value,
                 sizeof (((struct global *)item)->authfile));
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);
        return -1;
    }
    return 0;
}

int set_autodial (char *word, char *value, int context, void *item)
{
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_LAC:
        if (set_boolean (word, value, &(((struct lac *) item)->autodial)))
            return -1;
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);
        return -1;
    }
    return 0;
}

int set_flow (char *word, char *value, int context, void *item)
{
    int v;
    set_boolean (word, value, &v);
    if (v < 0)
        return -1;
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_LAC:
        if (v)
        {
            if (((struct lac *) item)->call_rws < 0)
                ((struct lac *) item)->call_rws = 0;
        }
        else
        {
            ((struct lac *) item)->call_rws = -1;
        }
        break;
    case CONTEXT_LNS:
        if (v)
        {
            if (((struct lns *) item)->call_rws < 0)
                ((struct lns *) item)->call_rws = 0;
        }
        else
        {
            ((struct lns *) item)->call_rws = -1;
        }
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);
        return -1;
    }
    return 0;
}

int set_defaultroute (char *word, char *value, int context, void *item)
{
    switch (context & ~CONTEXT_DEFAULT)
    {
    case CONTEXT_LAC:
        if (set_boolean (word, value, &(((struct lac *) item)->defaultroute)))
            return -1;
        break;
    default:
        snprintf (filerr, sizeof (filerr), "'%s' not valid in this context\n",
                  word);